@burglekitt/gmt-biome

Shared Biome configuration for @burglekitt/gmt projects. Enforces the Temporal-only policy by banning all Date APIs via Grit plugins.

Installation

npm

npm install --save-dev @burglekitt/gmt-biome @biomejs/biome

yarn

yarn add --dev @burglekitt/gmt-biome @biomejs/biome

pnpm

pnpm add --save-dev @burglekitt/gmt-biome @biomejs/biome

bun

bun add --save-dev @burglekitt/gmt-biome @biomejs/biome

Usage

Add the plugins to the plugins array in your biome.json. Biome resolves plugin paths as filesystem paths, so use the ./node_modules/ path with the .grit extension.

All rules (recommended)

Use the combined all plugin to enable every Date-ban rule in a single entry:

{
  "$schema": "https://biomejs.dev/schemas/2.4.11/schema.json",
  "plugins": ["./node_modules/@burglekitt/gmt-biome/plugins/all.grit"]
}

Select specific rules

Include only the plugins you need:

{
  "$schema": "https://biomejs.dev/schemas/2.4.11/schema.json",
  "plugins": [
    "./node_modules/@burglekitt/gmt-biome/plugins/no-new-date.grit",
    "./node_modules/@burglekitt/gmt-biome/plugins/no-date-now.grit",
    "./node_modules/@burglekitt/gmt-biome/plugins/no-date-parse.grit",
    "./node_modules/@burglekitt/gmt-biome/plugins/no-date-utc.grit",
    "./node_modules/@burglekitt/gmt-biome/plugins/no-date-getTimezoneOffset.grit"
  ]
}

Note: The .grit extension is required. When installed from npm, the typical path uses the ./node_modules/ prefix (as shown above), but any relative or absolute filesystem path to the .grit file on disk will work — Biome does not resolve npm package specifiers in plugins.

Why not extends? Biome's extends is for sharing biome.json config options (formatter, linter rules, etc.). It cannot be used to distribute GritQL plugins — plugin paths in an extended config file are always resolved relative to the consuming project root, not the npm package directory. Use plugins instead.

Banned patterns

| Pattern | Plugin | Suggestion | |---|---|---| | new Date(...) | no-new-date | Use getUtcNow(), getNow(), or getZonedNow(timezone) | | Date.now() | no-date-now | Use getUnixNow('milliseconds' \| 'seconds') or getNow() | | Date.parse(...) | no-date-parse | Use convertZonedToUnix(value) | | Date.UTC(...) | no-date-utc | Use convertUtcDateTimeToUnix('YYYY-MM-DDTHH:mm:ss', 'milliseconds' \| 'seconds') | | $date.getTimezoneOffset() | no-date-getTimezoneOffset | Use getZonedNow(timezone), other gmt zoned helpers such as convertZonedToUnix(value), or Temporal.ZonedDateTime |

Why Temporal?

Temporal solves fundamental issues with JavaScript's Date object:

• Immutability — no accidental mutations
• Timezone awareness — explicit, unambiguous timezone handling
• No DST bugs — proper daylight saving time logic
• Precision — nanosecond precision where needed

All banned Date APIs have Temporal equivalents that are safer, clearer, and more correct.